Calibration method considering second-order error term of timing skew for a novel multi-channel ADC

• Published in: 2011 9th IEEE International Conference on ASIC pp. 949 - 952
• Main Authors: Yong-sheng Yin, Rui Zhang, Jun Yang, Ming-lun Gao
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2011
• Subjects: Calibration; Estimation; Least squares approximation; Neodymium
• ISBN: 9781612841922; 1612841929
• ISSN: 2162-7541; 2162-755X
• DOI: 10.1109/ASICON.2011.6157363

The mismatch of timing skew between ADC channels restricts the performance of time-interleaved analog-to-digital converters (TIADCs) seriously. In our previous work, we proposed a novel 7-channel TIADC and its timing skew calibration based on dual-ADC mutual calibration, in which only the first-order term of timing skew is calibrated. In this paper, insufficiency of first-order calibration for timing skew is discussed and an improved calibration scheme, which calibrates the first two order terms of timing skew, is proposed. Simulation of the 14-bit TIADC with MATLAB shows that with timing skew in the range of ±0.02T s , and the normalized input frequency f in /f s =0.34, SNDR and SFDR of the output signal of the TIADC are only 50.7dBc and 53.2dBc, and reach 74.1dBc and 79.8dBc after first-order calibration. However, SNDR and SFDR achieve 86.1dBc and 105dBc after calibration through the improved scheme, and the TIADC performance is enhanced significantly.